This will show you how to export your RSS feeds from Outlook 2013 to any other program/service by OPML file.
Click FILE tab
Click Open & Export option
Click Import/Export button
Select Export RSS Feeds to an OPML file option. Click Next.
Select which feeds you want to export, then choose file name and path.
If you get similar error:
You do not have permission to save to this location.
Choose another location to save this file.You are probably trying to save file in root folder like c:file.opml. Choose any other folder to export the file, like c:tempfile.opml